The research showed high dose injections of the vitamin, also known as ascorbate or ascorbic acid, reduced tumor weight and growth rate by about 50 percent in mouse models of brain, ovarian, and pancreatic cancers.

Better yet, high doses of vitamin C did not affect normal cells while cancer cells were apparently killed by hydrogen peroxide formed in the extracellular fluid surrounding the tumors by the reactions involving vitamin C.

This is not the first time that vitamin C has been found to have an anticancer therapeutic effect. Some early studies showed that cancer patients who received conventional treatments AND used high doses of vitamin C lived much longer than those who were treated only with conventional therapies.

One study, part of the European Prospective Investigation into Cancer and Nutrition or EPIC initiated in 1992, which involved 521,000 people in 10 European countries, found those who had highest levels of vitamin C in the blood were significantly less likely to have stomach cancer.

Additionally, vitamin C may play an important role in protecting against cancer risk associated with diet high in meat, according to the study, which was published in the November 11 issue of the journal Carcinogenesis.

Dr. Mark Levine and colleagues at the National Institute of Diabetes & Digestive & Kidney Disease, authors of the current research, already published a study in the Sept 12-16, 2005 issue of the Proceedings of the National Academy of Sciences, a prestigious scientific journal saying that cancer cells were killed when a dose of vitamin C 25 times higher than the level that the blood can absorb was applied on cancer cell lines.

Studies also showed that high doses of vitamin C may help prevent and treat melanoma, the deadly skin cancer, breast cancer and oral cancer.   Some researchers speculated that vitamin C may also help leukemia, according to an unsubstantiated source.

Scientists at Johns Hopkins also reported in the Sept 11, 2007 issue of Cancer Cell that vitamin C has an anticancer effect against some types of cancer.

For the current study, Dr. Mark Levine and colleagues tested vitamin C on 43 cancer and 5 normal cell lines and found that high concentrations of ascorbate had anticancer effects on 75 percent of cancer cell lines while having no effect on normal cells.

The scientists further tested high dose injections of vitamin C in immune-deficient mice with rapidly spreading ovarian, pancreatic and glioblastoma tumors and discovered that mice that received vitamin C injections reduced tumor growth and weight by 41 to 53 percent.   30 percent of mice with glioblastoma that did not get vitamin C had spread to other organs while none of the treated mice had signs of disseminated cancer.

Humans like a few other species can't produce vitamin C, which plays a very important role in the body. Chronic deficiency of this vitamin can cause scurvy and even result in death.   But some researchers said just because you do not have scurvy does not mean your system has enough amounts of vitamin C.   Linus Pauling, a winner of two Nobel Prizes, advised people to use high doses and the dosage needs to be increased with age.

The anticancer effect of vitamin C has been well recognized in the Alternative medicine and some physicians have been using intravenous injections of high doses of vitamin C to treat cancer patients for years.

Vitamin C is one of the safest vitamins man can use. But its recommended dietary allowance is incredibly low.   Critics said most of early studies that failed to demonstrate the anticancer effect of the vitamin is because low doses were used.